Robert lundell



(No Medel.)

- 11.` LUNDELL.

ROTARY FAN. Ne. 511,442. Patented Dee. 26, 1893,

@XH/[Meana Y gnou/woz UNITED STATES PATENT OFFICE.

ROBERT LUNDELL, OF BROOKLYN, ASSIGNOR OF TWO-THIRDS TO EDWARDA I-I.JOHNSON, -OF NEW YORK, N. Y.

R O TA RY FA N SPECIFICATION forming part of Letters Patent No. 511,442,dated December 26, 1893.

Application filed January 4, 1893. Serial No. l457,261. (No model.)

.To all whom, it may concern:

Be it known that I, ROBERT LUNDELL, a citizen of the United States,residing at Brooklyn, in the county of Kings and State of New York,ha-ve made anew and useful Invention in Rotary Fans, of which thefollowing is a specification.

My invention is directed particularly to that type of rotary fanshavinginclined vanes or blades, such for instance as are now largely inpublic use in connection with electric motors for creating drafts ofair, and its objects are, first, the construction of a fan which shallbe as light as possible and therefore offer to the j ournalbearings ofthe motive power a minimum amount of friction: second, to avoid as faras possible the unnecessary vibrations and annoying humming noises whichexist with such fans when running at high speeds: third, to avoid thenecessity of the balancing of such a fan: fourth, to produce a fan whichwillby virtue of its lightness and peculiar construction be free fromthe dangers due to centrifugal force with such fans when running at highspeeds, and fifth, to produce a rotary fan which when running will notinjure a person coming in contact with its vanes or blades. sults areeffected by the novel fan hereinafter described, the essential featuresof novelty of my invention being particularly pointed out in the claimsat the end of this specification.

Rotary fans that have heretofore been devised have been made wholly ofmetal or wood and the vanes or blades thereof attached directly to theirhubs by rivets, said hubs` being secured to the axles of the propellingmotors in well known ways. Metal fans have also been devised in whichthe vanes or blades were cast solid with the hubs but in all-suchinstances the fans were of such weight as to materially decrease theirefciency when being driven and also endanger' the user either bythrowing `od the vanes when running at high speedsor bybeing too closelyapproached. My invention avoids all of these objections and will befully understood by referring to the accompanying drawings, in which`Figure l is a front elevational view of my improved fan with the clothor other equiva- These several relent material Vwhich constitutes thesurface of the vanes or blades in position on the lower vane and removedtherefrom on the upper vane of a two-bladed fan. Fig. 2 is a sideelevational view of the same, part of the cloth being broken away, thebetter to show the Structure.

Referring to the drawings in detail: A is the axis of the driving motor,preferably an electric motor not shown, and H the hub of the fan securedthereto in the usual manner by a set screw G, said hub having two ormore short hollow radial arms S S.

B B are supporting arms of tapered construction for the vanes or bladesas shown secured in the hollow arms S S of the hub by pins or screws FF, said arms being made preferably of some strong, light, elasticmaterial as wood. To the outer ends of each of these arms isattached astrong, thin cord or wire D which cords in turn are drawn taut, asclearly shown, through eyes E E integral with the arms S S, said cordsor wires being located on oppositesides and the entire arrangement ofthe drawn cords and arms B under tension constituting a frame work towhich is secured by thread, glue or in any preferred man ner, lightstrong vanes or blades C of oiled silk, thin leather, or any preferredmaterial of such a pliable nature. I prefer to use oiled silk and `tostretch the same as tightly as possible over the framework so as to makea neat and comparatively strong structure. It will be understood ofcourse that there may be any number of vanes or blades C and that thepitch of said vanes or blades may be arranged to suit the user by simplywithdrawing the pins or screwsl F F from the arms BB'and turning saidarms into any desired position after which the pins or screws may againbe inserted. I prefer to rotate the fan when in use in such way that thecords or wires D D cut the air as they advance as shown by the arrows inFig. 1.

It will be understood that any desired tension may be put upon the armsB by drawing the cords D through the eyes E and fastening them by tyingor in any preferred manner. I find that a rotaryfan of such structure isalmost absolutely noiseless when run at high speeds and that there is aminimum' amount of vibration upon the shaft thereby greatly increasingthe ecieneyof apparatus of this nature.

I do not limit my claims to the specific structure herein shown anddescribed as I believe it is broadly new with me io devise a rotary fanin which the vanes or blades are made of a pliable material such ascloth, silk, skin, paper, parchment or equivalent mate rial held undertension by a sustaining support or frame and my claims are generic inthis particular.

Having thus described my invention, what I claim, and desire to secureby Letters Patent of the United States, is

l. A rotary fan having vanes orblades made of pliable material sustainedby elastic or yielding arms and cords which put the arms under tensionat their outer ends substantially as described.

2. A rotary fan having vanes or blades made of pliable material attachedto radial arms adjustably secured in a hub at their inner ends and tocords at their outer ends which cords are in turn secured to the hubsubstantially as described.

3. A rotary fan having two or more vanos or blades made of pliablematerial stretched upon frames or supports consisting ot' curved radialarms attached t0 a common hub and cords which unite the outer ends ofthe arms Withthe hub substantially as described.

ROBERT LUNDELL. Wlitnesses:

CHAs. J. KINTNER, M. M. ROBINSON.

